Cetus & Delphinus
The Whale and The Dolphin
The constellations of the Whale and Dolphin match in a cosmic kind of way. Each name of the Constellations harmonize with a special partner. In this case two air breathing 'fish' are branded together as 'Fraternal Constellations.' Astronomers had a tendency to name things in pairs, on a subconscious level.
Both flags are in the Equatorial region of the Celestial Sphere, thus both get white stripes. Cetus's territory actually crosses the Cosmic Equator. Both cetaceans are rooted to Southern Galactic Sphere allied to Andromeda Galaxy.